WiMAX (IEEE 802.16)-profıbus arabağlaşım elemanının petri ağlarla modellenmesi ve performans analizi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Endüstriyel kontrol uygulamalarında saha seviyesindeki dağıtık kontrolör cihazların haberleşmesinde sahayolu ağları kullanılmaktadır. PROFIBUS (PROcess FIeld BUS) uluslararası standartlarla (IEC61158, EN50170) tanımlanmış en popüler sahayoludur. Üretim (fabrika), süreç ve bina otomasyon uygulamalarında yaygın olarak kullanılan PROFIBUS, 100 m ile 1200 m mesafede 9.6 kbps ile 12 Mbps arasındaki iletişim hızlarını desteklemektedir. Bu durum, PROFIBUS'ın daha geniş kapsama alanları ve yüksek hızlarda kullanılabilmesi için omurga teknolojisine sahip arabağlaşım elemanlarının kullanımını gerektirir.Arabağlaşım için kullanılan omurga protokolü gereksinimleri gelişen teknolojilerle birlikte değişmektedir. Günümüzde, kurulum kolaylığı ve hareketlilik avantajlarından dolayı kablolu omurga çözümlerine karşılık, kablosuz omurga çözümleri de kullanılmaya başlanmış ve hızla yaygınlaşmaktadır. Kablosuz genişbant omurga teknolojisi olan IEEE 802.16-WiMAX, görüş hattında 50 km'lik bir kapsama alanı, 120 Mbps veri transfer hızı ve farklı servis sınıflarında (UGS, rtPS, nrtPS, BE, ErtPS) hizmet kalitesi sunan bir protokoldür.Bu çalışmada, farklı lokasyonlardaki PROFIBUS segmentlerini IEEE 802.16-WiMAX kablosuz omurga teknolojisi üzerinden UGS servis sınıfı kullanarak birbirine bağlayan bir arabağlaşım birimi önerilmektedir. Bu birimin, senkronizasyon, koşutzamanlılık, kilitlenmeyi önleyebilme, üstel dağılım ve sabit zaman gecikme özellikleri olan Genelleştirilmiş Stokastik Petri Ağlar modeli sunulmaktadır. Ayrıca, model içerisinde PROFIBUS paketlerinin IEEE 802.16 paketleri içerisine kapsüllendiği önerilmektedir.Tasarlanan PROFIBUS/IEEE 802.16-WiMAX arabağlaşım birimi, geçit çıkış tampon boyutu, geçit giriş tampon boyutu, master istasyon jeton tutma süresi ve geçit PROFIBUS ayağı jeton tutma süresi parametrelerine bakılarak değerlendirilmiştir. Benzetimlerden alınan sonuçlar, arabağlaşım biriminin, farklı yükler altında yeterli bir hizmet sağladığını ve fiziksel gerçeklemesini yapacak olan kişiler için de başarımı ölçülebilir bir tasarım modeli sunduğunu göstermektedir.In the application of industrial controlling, fieldbuses are used in the communication of distributed controller devices at field layer. PROFIBUS (PROcess FIeld BUS) which is defined with the international standards (IEC61158, EN50170) is the most popular fieldbus. PROFIBUS which is used frequently in manufacturing (factory), process and building automations, provides datarates from 9.6 kbps to 12 Mbps at distance from 100 to 1200 meters. This situation requires using of internetworking units which has backbone technology, for using PROFIBUS at more coverage area and high datarates.The requirements of a backbone protocol used for internetworking, are changed by the development in technology. Nowadays, because of advantages of easiness in installation and mobility, in addition to the wired backbone solutions, wireless backbone solutions began to be used and rapidly became common. As a wireless broadband backbone technology, IEEE 802.16-WiMAX is a protocol that can serve a 50 km coverage area, a 120 Mbps datarate and a QoS at different service classes (UGS, rtPS, nrtPS, BE, ErtPS) in line-of-sight.In this study, an internetworking unit is proposed that interconnects PROFIBUS segments placed at different locations through a wireless backbone technology of IEEE 802.16-WiMAX by using UGS service class. By the features of synchronization, concurrent, deadlock avoidance, exponential distribution and constant time delay, Generalized Stochastic Petri Nets model of the unit is done. Also in the model, it is proposed that PROFIBUS packets are encapsulated into IEEE 802.16 packets.The designed PROFIBUS/IEEE 802.16-WiMAX internetworking unit is analyzed according to gateway output buffer size, gateway input buffer size, master station token holding time and gateway PROFIBUS side token holding time parameters. The outputs of simulations show that internetworking unit can support a sufficient service under different loads and present a designed model with a measurable performance for the people who want to implement it physically

Journal of Telecommunications and Information Technology, nr 4

kwartalni

Conceptual Models for Assessment & Assurance of Dependability, Security and Privacy in the Eternal CONNECTed World

This is the first deliverable of WP5, which covers Conceptual Models for Assessment & Assurance of Dependability, Security and Privacy in the Eternal CONNECTed World. As described in the project DOW, in this document we cover the following topics: • Metrics definition • Identification of limitations of current V&V approaches and exploration of extensions/refinements/ new developments • Identification of security, privacy and trust models WP5 focus is on dependability concerning the peculiar aspects of the project, i.e., the threats deriving from on-the-fly synthesis of CONNECTors. We explore appropriate means for assessing/guaranteeing that the CONNECTed System yields acceptable levels for non-functional properties, such as reliability (e.g., the CONNECTor will ensure continued communication without interruption), security and privacy (e.g., the transactions do not disclose confidential data), trust (e.g., Networked Systems are put in communication only with parties they trust). After defining a conceptual framework for metrics definition, we present the approaches to dependability in CONNECT, which cover: i) Model-based V&V, ii) Security enforcement and iii) Trust management. The approaches are centered around monitoring, to allow for on-line analysis. Monitoring is performed alongside the functionalities of the CONNECTed System and is used to detect conditions that are deemed relevant by its clients (i.e., the other CONNECT Enablers). A unified lifecycle encompassing dependability analysis, security enforcement and trust management is outlined, spanning over discovery time, synthesis time and execution time

Recent advances in petri nets and concurrency

CEUR Workshop Proceeding

Modelling bacterial regulatory networks with Petri nets

To exploit the vast data obtained from high throughput molecular biology, a variety of modelling and analysis techniques must be fully utilised. In this thesis, Petri nets are investigated within the context of computational systems biology, with the specific focus of facilitating the creation and analysis of models of biological pathways. The analysis of qualitative models of genetic networks using safe Petri net techniques was investigated with particular reference to model checking. To exploit existing model repositories a mapping was presented for the automatic translation of models encoded in the Systems Biology Markup Language (SBML) into the Petri Net framework. The mapping is demonstrated via the conversion and invariant analysis of two published models of the glycolysis pathway. Dynamic stochastic simulations of biological systems suffer from two problems: computational cost; and lack of kinetic parameters. A new stochastic Petri net simulation tool, NASTY was developed which addresses the prohibitive real-time computational costs of simulations by using distributed job scheduling. In order to manage and maximise the usefulness of simulation results a new data standard, TSML was presented. The computational power of NASTY provided the basis for the development of a genetic algorithm for the automatic parameterisation of stochastic models. This parameter estimation technique was evaluated on a published model of the general stress response of E. coli. An attempt to enhance the parameter estimation process using sensitivity analysis was then investigated. To explore the scope and limits of applying the Petri net techniques presented, a realistic case study investigated how the Pho and aB regulons interact to mitigate phosphate stress in Bacillus subtilis. This study made use of a combination of qualitative and quantitative Petri net techniques and was able to confirm an existing experimental hypothesis.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Modelling bacterial regulatory networks with Petri nets

To exploit the vast data obtained from high throughput molecular biology, a variety of modelling and analysis techniques must be fully utilised. In this thesis, Petri nets are investigated within the context of computational systems biology, with the specific focus of facilitating the creation and analysis of models of biological pathways. The analysis of qualitative models of genetic networks using safe Petri net techniques was investigated with particular reference to model checking. To exploit existing model repositories a mapping was presented for the automatic translation of models encoded in the Systems Biology Markup Language (SBML) into the Petri Net framework. The mapping is demonstrated via the conversion and invariant analysis of two published models of the glycolysis pathway. Dynamic stochastic simulations of biological systems suffer from two problems: computational cost; and lack of kinetic parameters. A new stochastic Petri net simulation tool, NASTY was developed which addresses the prohibitive real-time computational costs of simulations by using distributed job scheduling. In order to manage and maximise the usefulness of simulation results a new data standard, TSML was presented. The computational power of NASTY provided the basis for the development of a genetic algorithm for the automatic parameterisation of stochastic models. This parameter estimation technique was evaluated on a published model of the general stress response of E. coli. An attempt to enhance the parameter estimation process using sensitivity analysis was then investigated. To explore the scope and limits of applying the Petri net techniques presented, a realistic case study investigated how the Pho and aB regulons interact to mitigate phosphate stress in Bacillus subtilis. This study made use of a combination of qualitative and quantitative Petri net techniques and was able to confirm an existing experimental hypothesis.EThOS - Electronic Theses Online ServiceGBUnited Kingdo